Temperature, Energy

Question 1

Stefan Boltzman

Answer 1

Intensity of energy radiated by a black body increases according to the fourth power of its absolute temperature

Question 2

Weins

Answer 2

For any radiating body the wavelength of its peak emissions are inversely proportional to its absolute temperature

Question 3

Solstice and Equinox

Answer 3

Solstice - June/Dec where suns noon rays are vertical over the tropics, marks its most northerly or southerly position relative to the equator

Equinox - March/Sep where suns noon rays are vertical over the equator, day and night are equal in both hemispheres at all lat

Significance - solstices mark height of summer/winter in respective hemispheres and the points of the year where the energy imbalance between high and low lat is greatest, equinox mark the transition between the solstice and the point of the year where the energy imbalance is least

Question 4

Milankovitch cycle

Answer 4

Variations in the earths orbital path and position relative to the sun

Eccentricity - the earths elliptical path around the sun due to the gravitational effects of other planets (Jupiter and Saturn) acting to pull the earth away from sun. When the earth is closet (Perihelion) the energy received at all lat increases, when furthest away (aphelion) energy at all lat decreases. Inverse square law = the amount of energy received by a body decreases by the distance the energy travelled squared

Obliquity - the tilt of the earths rotational axis. Determines intensity of our seasons, at the equator where the sun strikes at a relatively direct angle there are no seasons and the amount of insolation received is great. While at higher latitudes the angle the sun strikes is more oblique so the radiation is spread over a larger surface and as it travels further more is lost to scattering and absorption.

Precession - the wobble of the earth around its rotational path due to the competing effects of gas planets Jupiter and Saturn. The cycle is 250,000 years and can alter strength and durations of seasons over long periods of time.

Question 5

Factors affecting atmospheric warming

Answer 5

Length of day - solstice, longer time of sun heating
Sun angle - solstice, sun at more vertical angle
Seasons - summer, more insolation and longer day
Atmospheric/surface composition - albedo and cloud cover

Question 6

Rayleigh scattering

Answer 6

scattering by particles small relative to wavelength

scattering of short wavelengths results in blue visible spectrum during day, longer path of travel at night results in red sky at night (blue light scat 10x more than red)

Question 7

MIE scattering

Answer 7

scattering by particles large relative to wavelength (aerosols/water droplets)

leads to whitening, all wavelengths scattered the same resulting in light blue/greyish sky